Healthy Pool of Enrollees Cited in Keeping Costs Down in Bellwether State

Premiums for health-law plans in California will go up 4.2% on average next year, an increase that the state's insurance marketplace said was limited partly due to the large and relatively healthy pool of enrollees it had attracted.

Nationally, 2015 rate changes for plans sold through marketplaces created under the Affordable Care Act will vary widely, with a mix of increases and some declines. But California is seen as a bellwether. According to federal statistics released May 1, the state had about 1.4 million of the 8 million...